Hampton Sides has written one hell of an Arctic adventure story. In the Kingdom of Ice is the tale of Lieutenant George Washington De Long and his crew aboard the USS Jeannette who, in 1879, attempted to find the North Pole through the Arctic.

Hashtags won't fix this. At some point we need to take action, to stand up and be counted against the brute force of the oil companies, lobbyists and politicians who willingly pollute our climate system.

There is no contradiction for global warming to cause dramatic sea ice loss in the Arctic and a slight expansion in the Antarctic. There is no doubt in my mind that the implications for polar bears habitat loss are serious and sobering.

This summer's record low sea ice extent has prompted speculation about how polar bears will be affected. Because polar bears depend on sea ice to catch seals, less sea ice can only be bad for polar bears. But it's not just this year's record low that is cause for concern.

If greenhouse gases continue to rise, all models predict that the planet is headed to a future with an Arctic that is ice-free in the summer. The predictions of when this will occur vary by model, from as soon as a decade or two from now to closer to the end of the century.